In particular, the card manufacturing method according to the invention proposes making a plurality of cards or card bodies in the form of a plate from which each card or card body is then cut out. The plate is formed by a plurality of electronic units and a resin that at least partially coats or embeds the electronic units. In order to do this, the method includes a step of placing a resin in liquid form on and/or underneath the plurality of electronic units.
EP Patent No. 0 570 784 discloses in one particular implementation, a method of manufacturing cards that include an electronic assembly, in particular a transponder, which is placed in a main aperture in a positioning frame. The transponder and the positioning frame are embedded in a binder that can be added in viscous liquid form, particularly a resin. The positioning frame in EP Patent No. 0 570 784 is used only for delimiting an internal area for the transponder, formed of an integrated circuit and a coil, inside the card. Thus, when pressure is applied on the various elements and the binder to form a card, the transponder is held in an inner area of each card, while the binder can extend to form a layer that passes across the cards. Those skilled in the art can thus find in this Patent a card manufacturing method that allows transponders or other electronic units of various and even complex shapes to be integrated in the cards. However, providing and depositing the resin and on and/or underneath the electronic units and the positioning frame is a difficult step, especially when the electronic unit has a complex shape of variable thickness.
It is an object of the present invention to propose an improved manufacturing method for reducing the presence of residual air bubbles in the manufactured cards by providing resin in viscous liquid form. It is another object to improve the flatness of the cards obtained.